/*
 * Copyright 2002-2018 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.web.server.handler;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import reactor.core.publisher.Mono;

import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.web.server.ResponseStatusException;
import org.springframework.web.server.ServerWebExchange;
import org.springframework.web.server.WebExceptionHandler;

/**
 * Handle {@link ResponseStatusException} by setting the response status.
 *
 * @author Rossen Stoyanchev
 * @author Sebastien Deleuze
 * @since 5.0
 */
public class ResponseStatusExceptionHandler implements WebExceptionHandler {

    private static final Log logger = LogFactory.getLog(ResponseStatusExceptionHandler.class);


    @Override
    public Mono<Void> handle(ServerWebExchange exchange, Throwable ex) {
        if (ex instanceof ResponseStatusException) {
            HttpStatus status = ((ResponseStatusException) ex).getStatus();
            if (exchange.getResponse().setStatusCode(status)) {
                if (status.is5xxServerError()) {
                    logger.error(buildMessage(exchange.getRequest(), ex));
                } else if (status == HttpStatus.BAD_REQUEST) {
                    logger.warn(buildMessage(exchange.getRequest(), ex));
                } else {
                    logger.trace(buildMessage(exchange.getRequest(), ex));
                }
                return exchange.getResponse().setComplete();
            }
        }
        return Mono.error(ex);
    }

    private String buildMessage(ServerHttpRequest request, Throwable ex) {
        return "Failed to handle request [" + request.getMethod() + " "
                + request.getURI() + "]: " + ex.getMessage();
    }

}